An eminent Indian scientist announced he would return a prestigious government award to protest the "growing climate of intolerance" under the government of Prime Minister Narendra Modi.

Pushpa Mittra Bhargava, 87, is the latest to join dozens of prominent writers and film-makers who have returned awards over what they say is a growing disregard for freedom of speech.

"The future of democracy is at stake. I am very concerned about it," Bhargava, who was awarded the country's third highest civilian award - Padma Bhushan - in 1986, told the Hindu newspaper last week.

Echoing similar concerns, Apoorvanand Jha, an activist and professor of Hindi literature at Delhi University, told Al Jazeera that "writers have been forced to take a public stance" against the shrinking space for free speech.

Prominent Gujarati writer Ganesh Devy, who also returned his Sahitya Akademi award , said a "different point of view is not appreciated under this government".

PEN international, a global association of writers, has come out in solidarity with Indian protesters, calling on the government to safeguard free speech.

The killing of renowned scholar Malleshappa Madivalappa Kalburgi in August and the murder of intellectual Govind Pansare in February has rattled India's intelligentsia.

Though no group has so far claimed responsibility, hardline Hindu groups have threatened Kalburgi over his views against idol worship.

The Sahitya Akademi - India's National Academy of Letters - condemned the attacks on writers, but only after more than two-dozen authors parted ways with their awards in protest.

The Rashtriya Swayamsevak Sangh (RSS), of which Modi is a lifelong member, is a Hindu nationalist organisation and the ideological parent of the ruling Bharatiya Janata Party (BJP).

"The government is controlled by the Rashtriya Swayamsevak Sangh, which is intolerant and, therefore, it has no ability and desire to protect individual freedom," Devy told Al Jazeera.

Sudhanshu Trivedi, national spokesman of BJP, said it's an "ideological fight, which is being fought in the disguise of literary fight".

Devy said, however, that the protests by intellectuals do not fall along ideological lines.

"So many thinking people, sensitive people, think that the idea of India as plural, democratic and respect for diversity is under threat," he said. "I don't belong to any party, and I have fought the [opposition] Congress party in the past."

Twitter has turned into a battlefield with opposing sides hurling caustic comments to push their stance.

The recent lynching of a Muslim man in Uttar Pradesh state over rumours that he ate beef has also triggered widespread condemnation.

Days after the incident, acclaimed Indian author Nayantara Sehgal, niece of former Prime Minister Jawaharlal Nehru, returned her Sahitya Akademi award to protest against a "reign of terror".

"Rationalists who question superstition, anyone who questions any aspect of the ugly and dangerous distortion of Hinduism known as Hindutva - whether in the intellectual or artistic sphere, or whether in terms of food habits and lifestyle - are being marginalised, persecuted, or murdered," Sehgal, 88, said in an open letter.

Author Salman Rushdie was quick to lend support to Sehgal in a tweet, but the Booker Prize winner faced an avalanche of hateful responses.

Prime Minister Modi's "silence" over actions by Hindu nationalist institutions is leading to a new "degree of thuggish violence" in India, Rushdie told NDTV.

Anger in Kashmir after lynching over beef

But the BJP's Trivedi responded: "The prime minister will act on concrete facts provided by respective governments, not by the reports of the media."

Critics allege that Modi - who won last year's national elections on the promise to bring development to all - has turned a blind eye to the anti-minority activities of hardline groups allied to his party.

"Prime Minister Modi is pitting one community against the other. India is very fast moving towards a Hindu majoritarian state," Apoorvanand said.

"We are trying to imitate Sri Lanka of Mahinda Rajapaksa . Sri Lanka experimented with majoritarian language. They effectively silenced Tamil Hindus and Muslims. India is now following that."

Many of those arrested over the Dadri lynching are related to BJP leaders, but Trivedi denied any connections to his party. He said all recent crimes against government critics and minorities have happened in states where his BJP party is not in power.

However, Apoorvanand challenged that assessment. "The government is arrogant. It won't respond as it is blinded by a huge parliamentary majority."

The Hindu nationalist RSS has long been critical of the opposition Congress party for embracing what it calls foreign values and political systems when the constitution was adopted after independence in 1947.

In February, the chief of RSS, Mohan Bhagwat, declared that India was a Hindu Rashtra, or nation, despite the country's constitution defining it as secular.

"Writers, artists and scientists feel that one of the constitution's basic structures, secularism, is under attack," Apoorvanand said.

Critics say Hindu nationalist groups have been emboldened after the BJP came to power last year and are now loudly vocal about their demands.

Indian authors protest right-wing attacks

Issues such as cow protection, forced conversions , interreligious relationships , and the rewriting of India's history have made more headlines than key economic and bureaucratic reforms.

Last month, activists from Hindu nationalist party Shiv Sena smeared black paint on the face of Sudheendra Kulkarni, a former diplomat, at the book launch by Pakistan's former Foreign Minister Khurshid Ahmed Kasuri in Mumbai, capital of Maharashtra state.

Shiv Sena, another BJP ally, also forced the government to cancel a concert by popular Pakistani singer Ghulam Ali.

Devy said he was proud being born in a democratic country with a variety of different religions, 780 languages, and hundreds of distinct communities.

"All these diversities is our pride, our precious gift. In order to maintain that diversity, we need tolerance towards different ways of life, attitudes, languages, and religions. But that tolerance is shrinking," said Devy.